[David]

'No person except a natural born Citizen, or a Citizen of the United States, at the time of the Adoption of this Constitution shall be eligible to the Office of President; neither shall any Person be eligible to that Office who shall not have attained to the Age of thirty-five Years, and been fourteen Years a Resident within the United States.'

Care to explain?

Explain what? That is Article II, Sec. 1, Par. 4 of the U S Constitution. The important word is "eligible"--even if he gets elected, all of his acts as President, each one, one at a time, are subject to challenge as void and unlawful because he can not hold the office.

[Gondring]

Please look at the part I put in bold. It highlights what you asked.